On a slip of paper inserted into vinyl copies of the Grateful Dead's self-titled 1971 live album (popularly referred to as "Skull and Roses" because of its cover art), Jon McIntire, the group's manager, made a simple query: "DEAD FREAKS UNITE: Who are you? Where are you? How are you? Send us your name and address and we'll keep you informed. Dead Heads."

With that early attempt at social networking, Mr. McIntire, who died Feb. 15 of complications from lung cancer at his home in Stinson Beach at age 70, turned the group's disparate legion of followers into one of the most significant and identifiable rock 'n' roll fan communities.

Mr. McIntire, a svelte blond figure who worked as a systems analyst at Fireman's Fund Insurance Co. before taking the job with the band, managed the Grateful Dead through some of its most successful phases.

Between 1970 and 1974, he oversaw the release of two of the band's classic albums, "Workingman's Dead" and "American Beauty."

"Jon was the manager at a critical time for the band," McNally said. "He recognized that it wasn't just a job, but that we were on a mission."

After taking a decadelong break to work with singer-guitarist Bob Weir as a solo artist, Mr. McIntire returned to his position with the Grateful Dead in 1984 and shepherded the band into the mainstream with its only Top 10 hit, "Touch of Grey," from the 1987 album "In the Dark."

"We were all psychedelic revolutionaries, and we all became great friends during that time," McIntire said in a 1988 interview with The Golden Road magazine. "We were willing to try anything."

He left his post in 1990.

Mr. McIntire was born Aug. 13, 1941, in Mount Vernon, Ill. His piano skills afforded him the opportunity to become a charter member of the Early Music Society of St. Louis. He also acted in regional theater. He attended Washington University and San Francisco State, where he met another of the band's managers, Rock Scully.

He also briefly worked as co-manager of the Carousel Ballroom at Market and South Van Ness.

Following his time with the band, Mr. McIntire moved to St. Louis to resume his acting career and to work as a counselor for victims of domestic violence, while staying involved with the Grateful Dead as a member of the board of its charitable organization, the Rex Foundation.

He worked in theater in Newport Beach (Orange County) and New York before returning to Northern California last year.

"His influence on the band was in dignity and holding people to very high standards," McNally said. "For Jon, it wasn't about the money. He was concerned about our audience."